The final example starts with a large vessel and a different concept altogether.
It probably makes much more sense to start with a RORO design than a general cargo or container vessel because they are designed with large transverse decks specifically for vehicles and containers, although containers are usually secured in cassettes rather than cellular guides in a container ship.
In Part 1 I looked at the various types of larger vessel, in particular the different flavours of Roll On Roll Off designs. If we start with a conventional RORO the main problem is a lack of accommodation, this means the overload accommodation required for mission personnel will have to be provided by either a semi-permanent module or significant re-build that might cause complications with safety and compliance.
The MV Cragside has taken the latter option.
The MV Cragside is very similar, and has the same builder, as the UK’s Strategic RORO vessels.
The 1998 SDSR recognised the need for a strategic RORO capability in light of increasing expeditionary requirements and likely trends in the commercial shipping sector. It was predicted that RORO vessel size would increase and evolve leading to a reduction in charter availability. The ships would replace the RFA Sea Crusader and RFA Sea Centurion. A contract was let in 2000 to the AWSR Shipping consortium comprising Andrew Weir, James Fisher, Bibby Line and Houlder Hadley Shipping after competing bids from Novomar, Maersk and Sealion failed. The £1.25 billion PFI specified that 4 of the 6 vessels would be used by the MoD exclusively and the remaining pair available for commercial charter but one on 30 days and the other on 30 days notice to return to MoD service.
AWSR subsequently placed an order for 6 vessels to a German company, Flensburger Schiffbau Gesellschaft or FSG. FSG were to build 4 and Harland and Wolff, the remaining two. Hurst Point, Beachy Head, Eddystone and Longstone were the FSG built ships and Anvil Point and Hartland Point built by Harland and Wolff. Crews are British when on MoD service and Sponsored Reserves, in a similar model to that used by the Heavy Equipment Transport PFI. AWS provide the ship management arrangements, Bibby, crew management, Houlder the finance and construction management and James Fisher a range of other support activities. 18 months ahead of schedule the ships were fully available for service in 2003 and the PFI agreement expires in 2024.
The design chosen was the RoRo 2700, an existing 23,235 tonne design.[tabs] [tab title=”Hartland Point”]
All ships have the same characteristics except Beachy Head, Eddystone and Longstone that have more powerful 9 cylinder 8,100kw engines than the others and therefore have a maximum speed of 21 knots; Hurst Point, Anvil Point and Hartland Point have a maximum speed of 18 knots. All have bow thrusters and a crew of 22.
The ships are 193m long, 26 metres wide and have a draught of 6.6m
Their capacity is listed as 2,700 lane metres, trailer capacity is 35 on tank top with a maximum height of 5m, 62 on the main deck with a maximum height of 6.8m and 67 on the upper deck with a maximum height of 6.8m. Container stowage capacity is 72 TEUs on the tank top, 272 TEUs (double stacked) on the main deck and the 324 TEUs (double stacked) on upper deck, all these on Mafi trailers. Direct stow container capacity is approximately 411 TEU with 60 10kw/32A reefer plugs available for refrigerated containers.
Access to the decks is via a side ramp and a 16.4m long by 17.0m wide stern ramp and internal ramps to all decks. The stern ramp has twelve 2.7m wide fingers to enable access to narrow linkspans. Tests have also been conducted to prove the stern ramp can access a Mexeflote at sea for transfer to other ships or direct offloading to shore. None of the ramps are self supporting but the stern ramp has a rated capacity of 85 tonnes and the side ramp, 75 tonnes. The deck crane has a capacity of 40 tonnes at 25m outreach and 36 tonnes at 28m outreach. Drivers accommodation is in in 6 two berth cabins.[tabs] [tab title=”Mexeflote Access 1″]
The contract has operated with little fuss and no problems but as as part of the 2010 Strategic Defence and Security Review an evaluation of needs and costs came to the conclusion that the two non permanent vessels could be released from the contract. Longstone and Beachy Head were subsequently sold to CLDN becoming the MV Finnmerchant and MV Williamsborg.
In March 2013 the management contract was extended with Andrew Weir Shipping to 2024 and a number of consolidations have seen Foreland Shipping, the owner and operator of the vessels, now fully owned by the Hadley Group. The UK offers the residual capacity of the 4 permanently available vessels to the NATO Sealift Consortium as part of the Sealift Capability Package (SCP). This also includes three RORO ships on assured access, residual capacity of 5 Danish/German ARK RORO ships and a single Norwegian vessel.
One of our readers has even produced an image of a conversion…
With the contract finished in a few years, it might be an interesting option to explore.
Some might even be tempted by the ‘fastcat’ type short route ferries but just to show a couple of alternatives, a new RO-CON design by Knud E Hansen for the former National Shipping Company of Saudi Arabia (now Bahri) and a concept for a banana carrier, from the same company.[tabs] [tab title=”Bhari and Bananas”]
[/tab] [tab title=”Banana Reefer”]
Bahri have taken delivery of six vessels of this design, all built between 2013 and 2014, for the princely sum of £49 million each, no, that is not a spelling mistake.
They are designed with RORO, container and heavy lift on cargo in mind, flexibility built in. Each is 220m long, 32m beam and a maximum draught of 9.5m, with maximum speed of more than 17 knots.
The self-supporting rear quarter ramp has a capacity of 250 tonnes, the two 120 tonne capacity cranes can be operated in tandem for heavy loads and the total deck area is 24,000 m2. The forward open deck is designed for heavy lift cargo.
The Caribbean to Europe banana transport sector has some very specific requirements and this design supports much faster loading than using conventional High Cube reefer containers. Faster loading and unloading allows the vessel to slow steam, thus saving fuel and reducing emissions. For the backhaul leg of the journey, the RORO design allows the space to be optimised for car and truck transport. When used for carrying cars and trucks it has 4,400 lane metres. Read more about the subject of banana transport here.
Both designs have hoistable decks to optimise fill ratios and stern quarter ramps that allow loading and unloading without a RORO linkspan. The height of the various cargo decks could be optimised for modules and small craft, additional accommodation and lifting equipment added just like MSS (Small) and MSS (Medium).
However, am not going to take either of them forward with this section, they are here just to show what is possible from a design and cost perspective.
If not a RORO, what?
No, have not been on the Sherry, OK, maybe a little!
The point is a simple one, if modular mission payloads can be used at vehicle scale, why not at ship scale?
The previous two posts have concentrated on creating means and methods of handling containers, and container shaped loads.
There are a couple of similar examples to look at, the BMT OMAR Barge concept and the US Expeditionary Transfer Dock (ESD), formerly the Mobile Landing Platform, and the Expeditionary Support Base, formerly the Afloat Forward Staging Base.
They US systems both use a NASSCO modified Alaska Class Tanker as the base design.
The ESD serves as a transfer platform for LCAC hovercraft. Vehicles and stores are driven off Military Sealift Command (MSC) transport vessels and onto the ESD. LCAC’s ‘land’ on the ESD and the vehicles and stores are driven onto the LCAC.
For the second role (ESB), three of the five vessels, the large open space is fitted with a prefabricated module that has space for small craft, unmanned systems and helicopters.
Although many seem to focus on the more glamorous aspects of the ESB, the MCM role seems to be well suited to a future that includes and increasing reliance on off-board stand-off systems.
Squint at the images of the ESB and one could imagine it being quite similar to the proposal in the previous section, in reverse of course.[tabs] [tab title=”ESB 1″]
[/tab] [tab title=”Video 2″]
A few years ago BMT looked at the options for replacing RFA Diligence under the Operational Maintenance and Repair (OMAR) study.[adrotate group=”1″]
It concluded that the optimum solution was an unpowered barge carried to the area of operations on Float On Float Off (FLOFLO) heavy lift vessel. The barge was 120m x 30m and displaced approximately 3,500 tonnes.
The starting point for MSS (Large) is a heavy lift ship, a rather specialised design but one which has great potential for MSS.
Putting aside heavy lift barge/tug combinations, there are three basic configurations for a heavy lift ship;
Lift On Lift Off; the ship has a large open deck area onto which outsize and extremely heavy cargos are lifted on and off using dockside or integral cranes.
Roll On Roll Off; the payload is moved on-board using multi wheeled heavy lift platforms called Self Propelled Modular Transporters (SPMT). Ballasting allows a straight path to be established between the ships deck and quayside
Float On Float Off; the deck area flooded after ballasting down to an appropriate depth and the cargo manoeuvred in, usually with tugs, although when transporting smaller vessels, they can self-load. The ship is ‘re-floated’ and secured for the journey.
Different ships can use one or more of these methods, the most flexible being able to use all of them.
Operators include Jumbo Maritime, Bigroll, Dockwise, RollDock and Combilift. For transporting leisure craft, Yacht Transport provide a specialised service, the FLO-FLO vessels generally have higher capacity accommodation for the yacht crew.[tabs] [tab title=”Combilift”]
[/tab] [tab title=”RollDock”]
[/tab] [tab title=”Dockwise”]
[/tab] [tab title=”Yacht Transport”]
The Combi Dock is longer than the Roll Dock ST class, 170m and 151m respectively, but in other regards, they are very similar. Moveable deck panels are used to create a deck at one of six levels. A temporary bulkhead can also be installed to allow the vessel to be submerged without flooding the cargo hold. Their cranes can be used together for a tandem lift, approximately 700 tonnes. Total containers carried could also be 1,383 TEU if used in the transport role.
Although they are smaller than the FLOFLO heavy lift ships, their flexibility is extremely useful in the MSS role.[tabs] [tab title=”RORO”]
With a little shaved off the width, the BMT OMAR barge would fit perfectly on the cargo deck.
So, this is the starting point for MSS(LARGE), a multi-purpose, semi-submersible heavy-lift vessel approximately 170m long and 25m wide, the MV Combi Dock, a vessel that cost €100m to build, approximately £80m.
Interestingly, the later vessels in the series have been purchased and converted for use in the offshore industry
The OIG Giant II, formerly Blue Giant, formerly Combi Dock IV, is just such a conversion. The work included modifications to the cranes (anti heave and lift extension) and adding a helideck, moon pool, accommodation module, additional generators and a Dynamic Positioning system using azipods and thrusters. The 500 tonnes 13mx18m accommodation module is built across seven decks and includes facilities for 86 personnel, including leisure, sleeping, work spaces and water/waste treatment.
A new build contract at the same ‘offshore’ specification for two was reportedly €200m for the pair.[tabs] [tab title=”Blue Giant”]
We could go larger, some of the FLOFLO only ships can be very large, but to keep costs down, again, the modest option wins out.
Apart from adding a modest communications and sensor fit, the main modification area would be the cranes.
Do we need heavy cranes that can lift 350 tonnes for the MSS role?
If there were no FLOFLO or RORO capacity, there might be an argument for retention, but otherwise, there is no real need for them. The only thing they would be used for is lifting the hatch covers in and out of the cargo hold. Using a fixed crane, 3 in the case of the Combi Dock, allows the entire length of the cargo deck to be covered, but it does mean they have to be hefty enough for the weight at a specific outreach.
An alternative to the very expensive heavy lift cranes might be smaller travelling rail cranes such as those used in the offshore anchor handling industry. The large ones can lift 10-15 tonnes so when acting in tandem, a pair could easily lift the hatch covers.
A different view is that the cranes could be used for lifting small craft, or even larger patrol craft as part of a ‘mothership’ type approach. They would also be problematical if any of the larger modules used an aviation capability, obviously they would be a hazard. Leaving the centre crane in place but removing the other two would allow it to be stowed in a forward position for aviation operations but this would limit the amount of cargo deck it could cover, there would be gaps to the front and read.
This assumes the jib length is the same.
By accepting a lower lift weight than 350 tonnes, a longer jib length would allow a single crane, at the cargo deck mid-point to cover the entire deck. A 60m jib length crane, with heave compensation, is available from MacGergor, Liebherr and others. Passive heave compensation could also be used for traversing the splash zone.
A few different crane options to consider, but that would be about it for the changes.
There are two role categories, straightforward transportation and more complex missions that will likely include some form of module.
Roles – Without Modules
Over 1,300 TEU’s, a lot. They can be lifted on and off using harbour or the ships own crane. Containers could also be off loaded whilst at sea, the heave compensated crane allows much safer operation without pendulation. The containers could be loaded onto Mexeflotes, landing craft or other lighters. With a single crane, this would not be a particularly fast option though.
Containers could be simple dry types, tank containers or other specialist shelters.
A 20ft Tank Container, for example, could hold 24,000 Litres of water, fuel or other liquids.
At 4m width, 528 Lane Metres, with vehicles using a shore based loading ramp or lifted in and out. This would be across two decks using the standard hatch covers only, each deck being just over 4m high. There would also be space on the hatch covers if it were permissible to carry vehicles exposed to the elements.
The USMC used the MV Combi Dock III for just such a deployment
As with containers, the vehicles could be easily lifted onto lighters whilst at sea, in reasonable sea states.
Smaller craft such as patrol boats or MCM unmanned boats could simply be lifted from the deck into the sea. Using the two deck approach, the vessel could comfortably transport 110 Pacific 24 RHIB’s, more than we have in service.
Where this gets interesting though is with larger vessels.
A crane lift would be preferred because the lengthy docking down process would not be required.
With one crane, a 350 tonne limit allows a range of fast patrol craft, work boats and hovercraft to be transported to theatre. To be fair, we don’t actually have many of these, but with a credible deployment capability, we would be able to exploit the type of patrol craft we don’t have precisely because we have a need for global deployability but no means of doing it at short notice within our control. Anything up to 20m should be a simple lift, weather and sea conditions dependant.
To provide some sense of scale, a handful of examples.
Landing Craft Vehicle Personnel (LCVP) Mk5; these smaller craft are generally used for personnel only although they can carry small vehicles and light stores up to a weight of 6 tonnes. With a top speed of 24 knots the LCPV Mk5 is carried on davits on the assault ships (HMS Bulwark and Albion) and HMS Ocean. They have also been deployed from other vessels as deck cargo and deployed using cranes. The moveable and removable deck shelter provides essential protection against the elements for personnel aboard, a lesson from extensive operations in cold weather. The UK has 12 LCVP Mk5’s, obtained in two batches and purchased at a cost of £750k each. They are 15.7m long, 4.3m wide and have a range of excess of 200 nautical miles.
MSS (LARGE) could carry 21 LCVP Mk5 on a single deck, more than we have.
Army Work Boat; in addition to a number of Combat Support Boats, 51 (Port) Squadron RLC have four Army Work Boats made by Warbreck Engineering in Liverpool, subcontracted to VT Halmatic (now BAE). The four are named WB41 Storm, WB42 Diablo, WB43 Mistral and WB44 Sirocco, yes, the Army owns a Mistral! They are 14.75m x 4.3m, weigh 48 tonnes, have a top speed of 10 knots and are equipped with firefighting equipment. When deployed they are usually carried as deck cargo on a specially designed cradle and craned to the surface as needed. The Army Workboat can be used as tugs for Mexeflote’s, positioning other pontoon equipment and for handling flexible pipelines, especially those used in the JOFS fuel system described below.
MSS (LARGE) could carry 21 Army Work Boats, also more than we have.
Offshore Raiding Craft; Designed and built by Holyhead Marine, the Offshore Raiding Craft is in service with the Royal Marines used in insertion, patrol and security operations. The 9m craft are heavily armed and able to travelling at speeds up to 40 knots, available in three versions (mid, rear and front console), able to carry up to 8 personnel in addition to the 2 crew. Beam and draught are 2.9m and 0.6m respectively. The ORC trailer is supplied by Tex Engineering and with the ORC weighs 5.4 tonnes. They are powered by a 250hp Steyr Marine M256 engine driving a Rolls Royce FF270 waterjet’s. 39 are in service.
MSS (LARGE) could carry 44 ORC’s, more than we have.
Hovercraft; Feedback from operations in Iraq showed that whilst the in service Griffon 2000TD was able to withstand greater small arms damage than imagined, the crew were exposed so its replacement would need improvements in this area. The £1 million Griffon Hoverwork 2400 TD LCAC(L)(R) was a direct replacement for the 4 existing LCAC’s and feature armoured panels and bulletproof glass in addition to greater performance. The primary role of the LCAC (L) (R) is as an air-portable, fully amphibious craft capable of the high speed movement of 16 fully equipped troops and crew of 2 over water, ice, mud, marshland and beach. Able to maintain a speed of 45 knots whilst fully laden the replacement is much faster than the older version and there are a series of additional improvements. In addition to be being able to be deployed from the RN/RFA assault craft they are air portable by C130, A400 and C17. Their side panels can be retracted to reduce the width to enable air portability.
MSS(LARGE) could carry 16 2400 TD’s, more than, well, I think you get the picture!
Island Class; the CAMARC designed and Holyhead Marine manufactured Island Class Patrol Boats are used by the Royal Marines to protect high value Royal Navy shipping on the Clyde, Gare Loch and Long Loch. The pair (Mull and Rona) are a conversion of the more common 15m MoD Police patrol craft also used for similar duties. Six of the MoD Police variant were purchased in 2013 for £7 million, more since. They are 15m, 4.6m wide and have a draught of 1m. All have a high specification, ballistic panels, rescue equipment, security cameras and recording systems for example.
Archer Class; there are fourteen P2000 Archer Class Fast Inshore Patrol Craft in service, mostly tasked with supporting the University Royal Navy Units (URNU) but they are also tasked with other roles. 20m long and 6m wide, with a draught of 2m.
MSS (LARGE) could carry 12 of the 14 on the main deck, with remainder carried on the deck covers.
Scimitar Class; there are a couple of Scimitar Class patrol vessels in service with the Gibraltar squadron, they are 16m long and have a breadth of 3m, so yes, they could all be carried by MSS(LARGE)[tabs] [tab title=”LCVP Mk 5″]
[/tab] [tab title=”Archer”]
There are plenty of options for 20m patrol vessels and landing craft we don’t own, but I think you get the picture.
Using the Float-On-Float-Off loading method, even larger vessels can be transported and as long as their total height is no less than 8m, the hatch covers could be fitted for protection or even to allow other cargo (including smaller craft) to be carried on the top. Unless we have a burning desire to transport the 90m Offshore Patrol Vessels, which I guess would be kind of pointless, the main option would be the larger landing craft.
Landing Craft Utility (LCU) Mk10; Part of the programme for the Albion and Bulwark LPD’s were new Landing Craft Utility, Mk 10, replacing the Mk9’s carried aboard HMS Fearless and Intrepid. The LCU Mk10’s are large craft designed for transporting personnel, stores, armoured vehicles and large plant. Their roll on roll off design (stern and a bow ramps) is designed for ease of loading and unloading in the well dock of the assault ships. Up to 120 troops (100 in normal operating conditions), a Challenger main battle tank or other heavy or logistics vehicles can be carried. The LCU Mk10 can be used for general movement of equipment and operate independently for up to a couple of weeks with its 9 man crew out to a range of 600 nautical miles. Interestingly, the bow ramp can be used to lift an inflatable raiding craft out of the water when operating as a mother ship for raiding parties and such like. The LCU Mk10 is just under 30m long, with a beam of 7m, a draught of 1.7m when disembarking and a top speed of 9 knots. Click here for details of the engine and propulsion. A total of 8 LCU Mk10’s were bought into service in the £35 million programme, all delivered between December 2001 and February 2003 with a pair of prototypes in addition to the eight. The RORO capability is especially useful but as the wheelhouse impinges onto the load area at the stern it is not wide enough to accommodate a TES Challenger 2 vehicle and derivatives. Although not normally armed they have been seen recently with a range of automatic weapons on manually aimed mounts, mostly from ISTEC
MSS(LARGE) could carry 8 LCU Mk10, the full number in service.
Roles – with Maxi Modules
As can be seen from above, using MSS(LARGE) as a basic transport vessel with the ability to self load and offload would maximise the utilisation rates. In these roles, there are no facilities for embarked personnel, aviation or small craft handling.
What is a Maxi Module?
In the previous post, the concept of a modular payload was discussed and defined as that which could fit inside the dimensions of a 20ft or 40ft intermodal container. It is generally the definition widely used by everyone.[adrotate group=”1″]
For some roles though, fitting a module into a container actually makes the end solution sub-optimal, repair and medical especially. The notion of rapid changing modules is also flawed, module fits are much more likely to be changed on a deployment basis, or infrequently.
The ship is designed to accommodate very large constructions, weighing hundreds or even thousands of tonnes. FLO-FLO loading can accommodate a maximum load of 7,000 tonnes and RORO, 4,000 tonnes.[tabs] [tab title=”Heavy RORO 1″]
The Primary Casualty Receiving role, in reality, is used infrequently, major combat operations or unusual deployments like Operation GRITROCK, the ebola response. And yet despite this low usage rate, the demands of the role require a complex fit out, which means a dedicated vessel
This is the dilemma for some of these roles that are only valued in combat operations, they are infrequently used, and so a vicious circle appears. We might be able to allocate secondary roles to improve utilisation but the odds are always stacked against them in budget discussions.
Flexibility and maximum utilisation is the key attribute of MSS(LARGE).
Described above is the accommodation module for the OIG Giant, a 500 tonne single lift, 18m by 13m, with completely self-contained (even waste and power) and high specification facilities for 89 personnel. This is a Maxi Module, and to be perfectly honest, it is in widespread use in the offshore industry i.e. nothing new.
If we free ourselves of the notion that a module has to be 20ft long and 8ft by 8ft, a module can in fact, be very large.
Looking across the missions from the first part of this series, there becomes a requirement for a number of Maxi Modules.
Role 3 Hospital
There is no doubt that military medicine has progressed significantly during recent operations.
Upon the closure of the Role 3 Hospital at Camp Bastion, Lieutenant Colonel Jaish Mahan, Commanding Officer UK Medical Group, said;
Medical care is organised on a role or echelon basis, read more at the Allied Joint Doctrine for Medical Support. The MoD has also recently taken delivery of a modular deployable Role 3 Hospital from Marshall. The Queen Elizabeth aircraft carriers will have Role 2 facilities and Role 3 is currently provided by RFA Argus when designated in the role.[tabs] [tab title=”Health Support to Joint Ops”]
Facilities required include resuscitation, operating theatre, intensive care wards, advanced diagnostics (X ray, MRI etc), recovery wards, sterilisation, pharmacy, hyperbaric facilities, blood/blood component storage, medical waste disposal, command and control, laboratory, dental, isolation, medical gas handling, power generation, uninterruptible power supplies, storage space, catering, mortuary, laundry, extensive communications for telemedicine and a computing environment that supports the secure generation, storage and processing of large volumes of data.
As can be seen from the image above, the field hospital occupies a single layer but is approximately 120m by 60m. The Camp bastion diagram clearly shows a substantial layout and RFA Argus has an equally voluminous installation.
Maxi Modules need not be a single one piece construction, the Role 3 hospital for example, could comprise five or six large interlinked modules.
The examples below show typical offshore accommodation and production modules that are transported using the type of heavy lift ship proposed as the base for MSS(LARGE)[tabs] [tab title=”Module 1″]
When not on a deployment, the Role 3 maxi Modules would simply be stored onshore, they would also provide an excellent training environment or emergency capability.
Repair and Maintenance
For repair, maintenance and salvage, the Maxi Modules would be arranged to include heavy, electrical and composite workshops, electronic workshops, stores, personnel accommodation, helicopter landing facilities, stores lifts, power generations, compressors, extensive diver support
The heavy lift crane would be ideal for the role although a couple of smaller cranes might also prove useful.
Multi Mission Maxi Module (4M)
So first, try saying that after a few sherries, second, this will effectively look very similar to the MSS(MEDIUM) mission area, a large open space with handling systems, and aviation facilities above.
Because MSS(LARGE) has a longer, but narrower, cargo space, the actual configuration will be slightly different, accommodation for embarked personnel will also be required within the module, this would also include life raft, power and other services provision.
All the systems described in MSS(MEDIUM) would be incorporated into another series of large interlocking modules that could be rolled on to the bare platform.
A difference that might be worth exploiting is the FLOFLFO capability and ability to subdivide that. The module would go to the full depth of the cargo deck but some allocated to carrying the larger vessel.
In a ship to shore logistics or HADR operation, Mexeflotes and workboats for handling fuel pipes and manifolds would provide an invaluable addition. A couple of LCU Mk10’s, could be contained on a 35m open space to the rear would still leave approximately 100m for the module(s) and stores. Add a side loaded Mexeflote and that becomes a very capable ship to shore logistics capability.
Workboats; The SD Navigator is the name of the mooring and buoy handing Multi Cat 2510, and is an ideal workboat for Increment 1, equipped for buoy and mooring maintenance with winches and a 9 tonne at 7m outreach crane. A Damen Multicat 2510 would be an ideal general workboat for use in many HADR and logistics operations but because they are wide (for stability) they are too wide for easy road transportation or loading inside the LSD(A) well dock. Using two modules wide creates the 1205 and three wide, the 1908.[tabs] [tab title=”SD Navigator”]
[/tab] [tab title=”Damen 1205″]
Pontoons; the Mexeflote came into service with the British Army in the early 60’s, a result of work carried out at the Military Engineering Experimental Establishment (of Bailey Bridge fame). Technically, it is called the Harbour and Landing Ship Logistics Pontoon Causeway Equipment, the Mexeflote is elegant in its simplicity. Comprising three types of hollow steel pontoon sections with internal bulkheads they can be pinned together to form lighterage rafts, jetties, piers and floating platforms in the manner of big boys Lego. The pontoon sections can be carried individually and assembled in-situ but the norm is for the assembled raft to be secured to the sides of the carrying vessel for transit and when required, simply lowered or free dropped into the water. When in the water the propulsion units are craned over the side and secured in place and that is it, they are more or less ready to go.
Total payload depends on the size of the assembled pontoon;
- a. The Type A raft is 20.12 metres x 7.32 metres x 1.45metres. Capacity 60T
- b. The Type B raft is 38.41 metres x 7.32 metres x 1.45 metres. Capacity 120 T
A Maxi Mexe configuration is also possible and this has a rating of 180 tonnes. The older Z Drive propulsion units have now entirely been replaced with OD150N units from Thrustmaster.[tabs] [tab title=”Mexeflote 1″]
Larger patrol vessels would equally be a valuable contribution to the maritime and littoral security role, when combined with UAV’s and helicopters.
A 30m patrol vessel would still be able to be loaded in pairs or triplets whilst still leaving 100m of cargo deck for the module. This would also allow a mix of manned and unmanned vessels in the MCM role. Again, there are many off the shelf examples, the Ctruk Thor 19, Damen Stan Patrol 3007, Austal 30m Patrol Boat, Safeboats Mark VI or the 25m Patrol Boat designed by Camarc for the Royal Gibraltar Police.
Operating a small UAV like the Boeing/Insitu Scan Eagle or the larger Integrator should be a relatively simple activity and the latest sensors are showing enormous promise in the large area surveillance role. The Sentient Vision’s Kestrel Maritime ViDAR optical detection system has recently been trialled by the Royal Australian Navy (RAN) and showed over a three day trial how it could provide broad area surveillance, a 12 hour flight covered 13,000 square nautical miles.[tabs] [tab title=”Austal 30m”]
[/tab] [tab title=”Safeboats Mk VI”]
[/tab] [tab title=”VIDAR”]
Again, many options, off the shelf.
This approach is different than the others because it is specifically about maximising utilisation by using a multi-purpose lifting platform that has utility in the transport role. Extending the utility with demountable modules, albeit large and heavy modules, will maximise that utilisation.
Of all three approaches, this has the maximum flexibility.